Picture changer

ABSTRACT

The picture changer comprises a housing with a window and a slider member, on the actuation of which a pile of pictures housed in the changer is cyclically rearranged. To simplify construction and give the change-over movement any easy action, the process of separating the individual picture, which takes place under strong spring bias, is restricted to a short partial travel. As the change-over movement continues, the individual sheet is stiffened in the conveying direction so that it holds the remainder of the pile at a distance from the separating gap and itself is held by stop members. The change-over function can be interrupted by displacing the separating gap.

The invention concerns a picture changer, as described and illustratedin the prior patent applications mentioned below: PCT/EP85/00608,PCT/EP85/00615.

The forces that have to be applied when separating an individual picturecan be quite considerable, and because the individual parts of thepicture changer cannot be manufactured or assembled without tolerancevariations, the separating devices are held in active engagement bybiassing springs. This spring bias ultimately acts between the housingframe part and the slider member frame part, increases the friction, andnecessitates complicated measures to avoid wear and tear.

The invention is based on the problem of constructing a picture changerof this kind in such a manner that it acts easily, and can bemanufactured economically with few individual parts.

The solution according to the invention will become apparent from theindependent patent claims.

The first aspect of this invention relates to the fact that theseparating force for detaching the individual picture from the remainderof the pile is applied only over a slight partial path of the slidermember, namely at the start of the slider member withdrawal.

A further aspect of the invention relates to the fact that, over thefurther path of the slider member, the remainder of the pile is held ata distance from the picture through-gap of the separating device by aspecial deformation of the separated picture.

A further aspect of the invention relates to a novel combination of theseparating means and a device which enables the change-over function tobe interrupted.

A further aspect of the invention concerns the construction of retainingsystems which hold the individual picture securely in one frame part andsafeguard it against becoming twisted.

A first such system comprises a special embodiment of a system ofpressure springs such that a part of the same simultaneously forms apart of such a retaining system. A second retaining system comprisesstop members integrally moulded on one of the frame parts, the sheetbeing presented to these stop members in such a manner that it is unableto slip off them. A third retaining system comprises an element which isarranged in the first frame part, is provided with teeth and which canbe displaced in the direction of movement of the frame parts between anactive and an inactive position.

Finally, a further aspect of the invention concerns a modifiedconstruction of the separating means, in which a spring bias between theseparating elements defining a through-gap is not absolutely necessary.

Examples of embodiments of the subject of the invention are described indetail hereinafter with reference to the accompanying drawings.

FIG. 1 shows a longitudinal section through a picture changer accordingto the invention after the start of the rearranging operation,

FIG. 2 shows a perspective view of a component of the changer,

FIG. 3 is a section analogous to FIG. 1, but in the closed position ofthe changer,

FIG. 4 is a cross-section through the changer of FIG. 1 in the region ofthe separator bar,

FIG. 5 shows a later phase of the rearranging operation in a viewanalogous to FIG. 1,

FIG. 6 shows an analogous following phase,

FIG. 7 is a plan view onto one of the two symmetrically arrangedsprings, shown pressed down flat,

FIG. 8 shows, in a view similar to FIG. 4, a section in the separatorregion in the position of the frame parts shown in FIG. 6,

FIG. 9 shows, schematically, and exaggeratedly, the effect of thepicture deformation shown in FIG. 8,

FIG. 10 shows, in a view similar to FIG. 1, the relative position of thecomponents when the removal element is actuated,

FIG. 11 shows schematically a variation of the retaining system for theindividual sheet,

FIG. 12 shows schematically a further modification of this system,

FIG. 13 shows in partial cross-section the retaining functional elementsof a further embodiment,

FIG. 14 shows, in a view similar to FIG. 13, the functional elements ina different operating position,

FIG. 15 shows one of the elements in a perspective view,

FIG. 16 shows this element in side view together with its control means,

FIG. 17 shows a perspective view, partially broken away, of a variationof FIG. 15,

FIG. 18 shows in partial plan view a modified separating means,

FIG. 19 shows one of the separating elements from below,

FIG. 20 is the accompanying side view,

FIG. 21 shows, analogously to FIG. 18, a further variation,

FIG. 22 is a schematicized longitudinal section to FIG. 21,

FIG. 23 shows, analogously to FIG. 18, a modified separating system, and

FIG. 24 shows the two separating elements in partial section.

In the following description, the terms "sheet" and "picture" are usedsynonymously; it is obvious that each sheet carrying visual informationis also a "picture".

In all the drawings the illustrations are substantially simplified andschematicized; as regards the details, the reader is advised to refer tothe prior applications mentioned in the introduction.

The picture changer (or sheet changer) comprises a first frame part 20,hereinafter referred to as the housing, having a viewing window 24preferably covered by a transparent pane 22. Opposite the viewingwindow, spring assemblies 26 are mounted on the floor of the housing 20.The free arms 50, 27 and 72 of the spring assemblies press the pile ofpictures 28 towards the viewing window.

A second frame part can be displaced relative to the housing in adirection parallel to the plane of the viewing window. This second framepart is referred to hereinafter as the slider member 30. It comprises afront grippable end 32, two lateral side-pieces 34 with bottom strips34a and an inner transverse wall 36 in the form of a separator bar. Thesprings 26 have access to the pictures between the side-pieces 34.

At the end of the housing 20 opposite the grippable end 32 there isarranged in the housing a first separating element 40 which cooperateswith the separator bar 36 as the second separating element. The firstseparating element 40 comprises a support 42 from which spring arms 44extend outwards on both sides (FIG. 4). At the free ends of the springarms 44 there are arranged stepped portions 46, the top sides of whichslope obliquely backwards. The first separating element 40 is in thiscase not stationary in the housing but can be displaced for a shortdistance (cf. FIG. 10) in the direction of movement of the slidermember. For this purpose, an externally accessible button 48 isintegrally moulded on the support 42. The first separating elementconsists of a plastics material that is not susceptible to cold flow, sothat the resilient properties of the arms 44 are not impaired even ifthe slider member is not completely inserted in the housing.

FIG. 7 shows that the arm 50 of the spring assemblies 26, on its sidefacing towards the pile, has been treated in such a way that frictionwith respect to the material of the pictures is increased. This can beeffected by coating it with a suitable material, by roughening it, or insome other way. In this embodiment, small teeth 52 have been pushed outin such a way that they extend in a direction opposite the withdrawaldirection of the slider member and thereby hold a picture firmly but donot hinder the insertion of the slider member with the remainder of thepile.

On the housing floor 54, close to the housing opening through which theslider member moves, there is provided a picture stop member in the formof projections 56. Several ribs, three in this embodiment, denoted bythe reference number 58, extend in the ejection direction of the slidermember. On the underside of the separator bar 36 there are providedprojections 60 on each side of the middle rib and projections 62 outsidethe outer ribs 58. As clear from FIG. 8, this results in a picture thatlies between the separator and the ribs being deformed in a wave-likemanner and thereby being stiffened in the longitudinal direction (i.e.in the withdrawal direction of the slider member).

The function of the changer is explained below:

FIG. 3 shows the initial position. The end of the pile nearest theseparator is pressed by the spring arms 50 against the viewing windowand the separator bar is located, viewed in the withdrawal direction ofthe slider member, behind the stepped portions 46, the spring arms 44 ofwhich are unstressed. The spring arms 72 furthest away from theseparator bar, which are provided with inclined hooks 66, likewise pressthe pile against the viewing window.

If the slider member is now pulled, a force is exerted by the separatorbar on the picture edges facing it. Because the separator bar has aninclined face, this force has a component acting in the ejectiondirection and a component directed away from the window 22.

The effect on the pictures differs, depending on whether they arechecked at their end furthest away from the separator bar by theinclined hooks 66 or on whether they are able to slide away uncheckedover the inclined hooks. These last pictures are simply carried along bythe separator bar. The pictures checked by the inclined hooks on theother hand slide with their edge facing the separator downwards alongthe inclined face thereof, whereupon the spring arms 50 are pressed awayfrom the window.

The underside of the separator 36 runs onto the oblique faces 74 of thestepped portions and with the stepped portion defines a gap which iswider than one picture thickness but narrower than the thickness of twopictures. The spring bias exerted by the spring arms 44 (or a differentbiassing system between the housing and slider member) keeps the gap tosize despite possible tolerances during this picture separatingoperation. The upper side of the stepped portions 46 is provided with arounded portion 76 so that line contact with the separator and thepicture respectively takes place, and even if there is any tilting thecorrect dimension of the step height, and thus of the gap width, remainsunchanged.

The picture that is lowermost in the pile (that is to say, the picturefurthest away from the window), checked by the inclined hooks 66, butnot, however, the picture immediately next to it, fits with its otherend edge into the gap. The force component of the separator effective inthe ejection direction ultimately overcomes the checking force of thehooks 66 which, because of their inclined position, slide off all thepicture edges, with the exception of that of the lowermost picture.

When the separator bar had slid over the stepped portions 46, there wasa danger that the second lowermost or even more pictures would remainbeneath the separator. In the known picture changers mentioned in theintroduction this is countered by the fact that for the entire travel ofthe slider member the spring force keeps the height of the gaprestricted to the thickness of one picture, which results in stiffnessof operation and an expensive degree of complexity. According to theinvention, a different solution is chosen here: the separated picturenow lies between the separator and the ribs 58 and in doing so is bowedas shown in FIG. 8. One can see that rounded "waves") are formed insidethe separator on which the pictures carried along with the slider member"ride". This is shown diagrammatically in FIG. 9. Because there is noforce component acting on the pictures in the remainder of the pilewhich would cause a deformation similar to that of the separatedpicture, the edge of even the second lowermost picture nearest theseparator is unable to "creep" beneath the separator bar. The ribs 58and projections 60/62 engaging like combs with one another are effectivepreferably for the entire length of the withdrawal movement of theslider member.

It must be stressed that this wave-like deformation of the individualpicture--which in the drawings is naturally illustrated in a somewhatexaggerated manner for the sake of clarity--is able to occur only if theedge of the picture was previously able to pass beneath the separator.This in turn is only possible if the positions of the inclined hooks,the stepped portions and the ribs are correctly coordinated with oneanother. Advantage is taken of this fact in order to be able to removethe complete pile using the slider member: if, in fact, this geometry isdisturbed, no picture change can take place and in the embodiment thechange-over function is thus "interrupted" in that the assemblycomprising support 42, arms 44, stepped portions 46 and button 48 isdisplaced by a given degree in the withdrawal direction of the slidermember (FIG. 10). The gap beneath the separator bar is in fact formedonly when even the lowermost pictures have been released by the inclinedhooks 66. The entire pile is supported by the ribs 58 and the slidermember side pieces 34a, respectively, at a level that is above (i.ecloser to the window 22) than the lower edge of the separator. If theslider member is then pulled, it transports the entire pile to theoutside. On re-insertion, the assembly 42-48, as described below, ispushed back into its "change-over function position" again: the support42 has an upwardly projecting lug 78 which, when the button 48 ispressed in manually, is positively guided or snaps resiliently into acomplementary recess 80 in the separator, but upon withdrawal of theslider member snaps out again on account of the limited travel of thesupport 42, and when the slider member is pushed back by the separatorrunning onto the stepped portion 46 or onto the lug 78, is pushed backuntil the change-over function position has been regained.

The assembly is, however, even during the change-over function, governedby a force in the withdrawal direction of the slider member exerted onit by the separator; to prevent a displacement of the assembly occurringunintentionally as a result thereof, the assembly is arrested in thechange-over position and can be manually released when the entire pileis to be removed and the displacement is intended to be effected. Forthis purpose, there is provided a projection 82 which snaps into theopposite housing edge and can be disengaged from this by undergoingresilient deformation.

To return to the change-over function:

The picture separated from the pile is now held at its one edge by thestepped portions 46 and at its other edge by the inclined hooks 66. Onfurther withdrawal of the slider member, the separator bar runs over thestepped portions 46, but the individual picture is not released therebyand is held gripped between the separator and the springs arms 50.Provision is made for the friction forces acting on the picture to besmaller on the side facing towards the separator than on the side facingaway from it, so that the picture cannot be carried along by theseparator. This can be achieved in various ways: the friction on theseparator side can be reduced by suitable choice of material, or arolling-action friction can be provided, and/or friction on the springside can be increased by roughening, choice of material and so on. Inthe embodiment described, small teeth 52 are pushed out of the materialof the spring, opposite which teeth the separator has a recess 86 sothat it does not abrade against the teeth during the return travel ofthe slider member. A special retentive covering could also be providedas an alternative to these small teeth. In this embodiment the smallteeth are arranged opposing the withdrawal direction of the slidermember; on return of the slider member towards the end of thechange-over operation the lowermost picture of the remainder of the piledoes not come into contact with the small teeth in a manner likely tocause damage, in particular because of the fact that it is held at adistance by means of the ribs 58 and/or the bottom strips 34a.

The described gripping action is effective in this embodiment forapproximately half of the slider member travel. It is obvious, however,that this method of gripping the separated picture could also be appliedto the entire slider member travel. The friction-increasing featureswould then be applied also to the spring arms 72, wherein the springassemblies could be of even simpler construction, namely in the form ofa continuous band. In this embodiment, however, the spring arms 72 arerun over by the runners 88 integrally moulded on the bottom strips 34ain order to depress these arms so that pictures that are to be insertedwith the slider member only partially pulled out are not obstructed i.e.do not get beneath the springs (i.e. between the spring arms 72 and thehousing floor).

Since, therefore, after about half the withdrawal travel the clampingaction is no longer effective in this embodiment, the separated pictureis kept under control in a different manner. Its end edge supported atthe start of the change-over operation by the hooks now positions itselfin front of the projections 56, because the separator bar 36 depressesthe picture, assisted by the action of the spring arms 50 which lift theother edge of the picture. It should be noted that, in general, thepictures, when they are photographs, are not completely flat, but arebowed in an unpredictable manner. If a picture is supplied by theprocessing firm bowed in a U-shape, about an axis which runstransversely to the withdrawal direction of the slider member and islocated on the window side of the picture, then there is a risk that theend edge of such a picture will lie not in front of the projections 56but higher than these. As a precaution against this case, provision ismade for ribs to extend along the floor in the withdrawal directionwhich cooperate with the separator bar 36 to bend the separated pictureabout at least one axis of curvature running approximately at rightangles to the axis of curvature of the picture. The two directions ofcurvature cannot exist side by side so that the constrained deformationby the action of the ribs/separator prevails. In this embodiment thefunction of the ribs is assumed by the ribs 58, which extend right tothe front to the ejection opening of the slider member. The separatedpicture therefore remains lying in front of the projections for the fullwithdrawal of the slider member.

As in the previously known picture changers, in this position of theslider member the separated picture is lifted by the spring arms50/72/,27 in front of the window and thus in front of the stop members90, so that it slides over the separator onto the pile on reinsertion ofthe slider member into the housing. The separator has a wedge-like face96 which, as the separator slides onto the stepped portions 46, preventsthese from being damaged in that they are pressed downwards against thebias of the spring arms 44. The change-over operation is thus concluded.

During the picture change operation there are several differentretaining systems acting in succession on the picture to be separated,yet one system never releases the picture until it has been taken overby another. In the embodiment, the systems are allocated specificportions of the travel of the slider member movement, but these can alsobe divided up differently. In an extreme case, one system can beeffective for the entire withdrawal travel of the slider member.

Each of the retaining systems acts preferably at two points on thepicture in order to prevent twisting.

The embodiment can be modified, for example, in that instead of thepile, the individual picture is transported by the slider member out ofthe housing and/or the picture is removed at the window side of the pileinstead of at the side farthest from the window.

FIG. 11 illustrates a variation in the construction of the spring arms72. Here, at the free ends a mechanism is arranged which, afterseparation of the picture, engage over the edge thereof and carry itdownwards when the runners run over the spring arms.

The mechanism comprises a hook 92 which is arranged on the spring armsuch that it is displaceable longitudinally. Its position during thefirst phase of the change-over operation is indicated by a broken line.As the runner runs on, it is displaced into the position illustrated bysolid lines, in which it snaps over the free edge of the picture andholds this firmly.

FIG. 12 shows a variation of this principle. The spring arm 72 (notillustrated) carries a rail 94 with an integrally formed detent steppedportion 96. At the free end of the rail a two-armed lever 100 isarranged to pivot about a pin 98; the lever is swivelled in thedirection of the arrow by the remainder of the pile 102 pushed by meansof the separator. On the other arm of the lever there is an angledmember 104 which extends in the opposite direction to the direction ofmovement of the remainder of the pile 102 and in the rest position ofthe lever 100 lies protected behind the stepped portion 96 with ablade-like edge 108 facing the individual sheet or individual picture106. When the lever 100 is pivoted, the blade-like edge engages thesheet 106, but can be run over by the separator bar if the latter iscorrespondingly recessed in the region of the rail. On the other hand,when the slider member is pushed back, the lever is displaced in theother direction until it is able to snap back into its position of restshown in FIG. 12, into which it is biassed by means of a spring (notillustrated).

FIGS. 13 to 17 illustrate variations of the retaining means which keepthe individual sheet in the housing. Unlike the first embodiment, inthis case a pair of rails provided with teeth 120 is not held by springbias in engagement with the individual sheet; on the contrary, theseparator bar 36 has projections 122 which hold the individual sheet onwithdrawal of the slider member (FIG. 13) in engagement with the teeth;it is apparent that in this case the toothed rails 124 assume thefunction of the ribs 56 of the first embodiment. FIG. 14 shows that therails 124 can be recessed behind protective rails 126, for example inorder to be able to remove the entire pile. For this purpose the tworails 124 are joined together by a cross-piece 128 to form a one-piececounter-element, which--compare FIG. 16--is displaceable relative to thefloor 132 of the housing for a short distance in that it is shifted tothe right (in FIG. 16) by means of the button 130 accessible from theoutside. As this occurs, wedge-like faces 134, integrally moulded on theundersides of the rails 124, slide over stop projections 136 behindwhich they drop into recesses 138, whereby the rails too are retractedrelative to the protective rails. A biassing spring 140 which is bracedagainst a bridge 142 integrally moulded on the housing floor safeguardsthe respective end position of the counter-element. In the position ofthe toothed rails 124 in which these are retracted, as illustrated inFIG. 15, a free end of the spring 140 behind the bridge projects upwardsand when the slider member is reinserted it presses against this end ofthe spring and displaces the counter-element into its functionalposition shown in FIG. 16.

FIG. 17 indicates that this displacement of the counter-element can alsobe performed on each rearrangement or change-over operation. Thecrosspiece 128 is extended on both sides beyond the rails 124 so that itcan be pushed back by the slider member side pieces; at the other endthe toothed rails 124 have lateral continuations 144 against which thecorresponding control pins of the slider member (not illustrated) strikewhen the slider member approaches its outer end position. In this mannerthe teeth 120 are retracted on each return travel movement of the slidermember and the lowermost sheet of the remainder of the pile need notslide over the teeth.

FIGS. 18 to 24 relate to a variation of the separating means with whichthe advantages described in the introduction are also achieved.

In these forms of embodiment, both separating elements are arranged onthe first frame part, the housing, and both are displaceable relative toone another in a direction which has at least one component parallel tothe direction of movement of the frame parts. In the embodiments,swivelling flaps 150 are pivotable about axes at right angles to theprincipal plane of the pile symmetrically with respect to a plane thatruns at right angles to the principal plane of the pile in the directionof movement of the frame parts through the centre of the device. Onlyone of these flaps is shown in each of the Figures.

FIGS. 18 to 20 show a first example. The separating means comprises asupport face 152 on the housing floor, a step 154 and a top face 156parallel to the support face as first separating element, while theflaps form the second separating element.

The flaps stand initially transversely to the direction of movement ofthe frame parts parallel to the step 154. When the separator 36 runs on,it pivots the flaps into the position shown in FIG. 20 in which theypass through complementary recesses 158 in the separator. In so doing,they push the remainder of the pile in front of them while theindividual sheet lies protected behind the step 154. When the separatorhas run completely over the flaps, they spring resiliently back intotheir initial position, a double-action spring 160 being provided forthis purpose (FIG. 19), one leg pressing on the flap 150 and the otherbeing braced against a projection 162. As the slider member returns, theflaps yield in the opposite direction as shown in FIG. 20 by a brokenline.

In the embodiment shown in FIGS. 21 and 22 the flaps are not restored totheir initial position by spring force, but remain at first on theindividual sheet and hold it against the support (FIG. 22). Each flap isjoined to a restoring lever 164 which, by way of a wire linkage system166 with a compensating spring 168, pivots the flap back when theseparator 36 runs onto a control extension 170 of the linkage system.

In the variation shown in FIGS. 23 and 24, each flap 150 has a basicL-shape with a working arm and a restoring lever 172. An extension 174of the restoring arm is passed over by a recess 176 of the separator asthe slider member is withdrawn and is then able to pivot behind theseparator when this meets the working arm and carries it along. Theremainder of the pile is moved along thereby, as before (the outline ofthe pile is shown by a dot-dash line), whilst the individual sheetremains lying protected behind the step. On the pivot pin 178 is anintegrally moulded square 182, against the outer faces of which therelies a leaf spring 184 fastened at 186 in the housing floor; the flaptherefore has two stable end positions between which it can movebackwards and forwards.

It is obvious that details of the individual forms of embodiment are becombined with one another in the manner expressed in the patent claims.

I claim:
 1. Device for the cyclic rearrangement of a pile of rectangular sheets, for example photographs, with a first (20) and a second (30) frame part which are movable backwards and forwards relative to one another and parallel to the principal plane of the pile, and with means which on movement of the frame parts backwards and forwards remove an individual sheet from one end of the pile and add said individual sheet to the other end of the pile again, which means comprise:(a) a separating means (36, 46) for separating the individual sheet from the pile, (b) a feeding means (66) for feeding sheets to the separating means, (c) retaining means (50, 52, 56) for retaining the individual sheet in the first frame part and the remainder of the pile in the other frame part, and (d) guide means for guiding the separated individual sheet for the purpose of returning said individual sheet to the other end of the remainder of the pile,wherein the separating means comprises a first (46) and a second (36) separating element which define a through-gap which for the entry of the sheet to be separated has an inside width of more than the thickness of one sheet and less than the thickness of two sheets, and wherein the two separating elements are biased resiliently towards one another only during an initial phase of the movement of the frame parts.
 2. Device according to claim 1, in which the height of the through-gap is limited by a stepped portion (46) provided on one of the separating elements.
 3. Device according to claim 2, in which the stepped portion (46) is provided on a resilient element.
 4. Device according to claim 1, in which the separating means is symmetrical with respect to a plane of symmetry running at right angles to the principal plane of the pile and parallel to the direction of movement of the frame parts.
 5. Device according to claim 4, in which a stepped portion (46) is provided on two sub-elements (44) biassed independently of one another.
 6. Device according to claim 5, in which each stepped portion (46) is provided on a spring arm (44).
 7. Device according to claim 6, in which the spring arms (44) extend transversely to the direction of movement of the frame parts.
 8. Device according to claim 7, in which the height of the stepped portion is independent of the magnitude of the spring displacement during the gap formation.
 9. Device according to claim 8, in which the stepped portions (46) have a rounded contour.
 10. Device according to claim 6, in which the stepped portions (46) and the spring arms (66) are of integral construction.
 11. Device according to claim 10, in which the stepped portions and the spring arms form a one-piece plastics part.
 12. Device according to claim 1, in which one of the separating elements (36) forms the holder for the remainder of the pile, while the other separating element is arranged on a separate insert (40) in the first frame part and during the initial phase of the movement of the frame parts is resiliently biassed towards the one separating element.
 13. Device according to claim 1, in which means are provided for deforming the individual sheet in such a manner that said individual sheet has curves which space the remainder of the pile from the through-gap.
 14. Device according to claim 1, in which the separating elements for blocking the through-gap during that part of the frame part movement for which the feeding means is active are manually displaceable relative to one another.
 15. Device according to claim 1, in which the individual sheet during at least a partial travel of the relative movement of the frame parts is brought by a separator bar, which holds the remainder of the pile, into contact with teeth arranged on a counter-element, which teeth hold the individual sheet, and wherein means are provided for preventing direct contact between the separator bar and the teeth.
 16. Device according to claim 1, in which the retaining means for retaining the individual sheet comprises stop members (56) against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts is positioned as the frame parts are moved apart, and in which means are provided for deforming the individual sheet in such a manner that its edge is positioned in front of the stop members for a least that part of the frame movement during which this edge should act against the stop members.
 17. Device according to claim 1, in which the retaining means for holding the individual sheet comprises stop members against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which means (92) are provided which engage over the individual sheet edge and hold said edge in front of the stop members and, controlled by the relative movement of the frame parts, release said edge again.
 18. Device according to claim 1, in which the two separating elements are arranged on the same frame part and are displaceable relative to one another in the direction of movement of the frame parts and controlled by this movement.
 19. Device for the cyclic arrangement of a pile of rectangular sheets, for example photographs, with a first (20) and a second (30) frame part which are movable backwards and forwards relative to one another and parallel to the principal plane of the pile, and with means which on movement of the frame parts backwards and forwards remove an individual sheet from one end of the pile and add said individual sheet to the other end of the pile again, which means comprise:(a) a separating means (36, 46) for separating the individual sheet from the pile, (b) a feeding means (66) for feeding sheets to the separating means, (c) retaining means (50, 52, 56) for retaining the individual sheet in the first frame part and the remainder of the pile in the other frame part, and (d) guide means for guiding the separated individual sheet for the purpose of returning said individual sheet to the other end of the remainder of the pile,wherein the separating means comprises a first (46) and a second (36) separating element which define a through-gap which for the entry of the sheet to be separated has an inside width of more than the thickness of one sheet and less than the thickness of two sheets, and in which one of the separating elements (36) forms the holder for the remainder of the pile while the other separating element is arranged on a separate insert (40) in the first frame part, and is biassed resiliently towards the one separating element only during the initial phase of the movement of the frame parts.
 20. Device according to claim 19, in which the height of the through-gap is defined by a stepped portion (46) provided on one of the separating elements.
 21. Device according to claim 20, in which the stepped portion (46) is provided on a resilient element.
 22. Device according to claim 19, in which the separating means is symmetrical with respect to a plane of symmetry extending at right angles to the principal plane of the pile and parallel to the direction of movement of the frame parts.
 23. Device according to claim 22, in which a stepped portion (46) is provided on two sub-elements (44) biassed resiliently independently of one another.
 24. Device according to claim 23, in which each stepped portion (46) is provided on a spring arm (44).
 25. Device according to claim 24, in which the spring arms (44) extend transversely to the direction of movement of the frame parts.
 26. Device according to claim 25, in which the height of the stepped portion is independent of the magnitude of the spring displacement during the formation of the gap.
 27. Device according to claim 26, in which the stepped portions (46) have a rounded contour.
 28. Device according to claim 24, in which the stepped portions (46) and the spring arms (44) are of integral construction.
 29. Device according to claim 28, in which the stepped portions and the spring arms form a one-piece plastics part.
 30. Device according to claim 19, in which means for deforming the individual sheet are provided in such a manner that the sheet has curves which space the remainder of the pile from the through-gap.
 31. Device according to claim 19, in which the separating elements for blocking the through-gap during that part of the movement of the frame parts for which the feeding means is active are manually displaceable relative to one another.
 32. Device according to claim 19, in which the individual sheet during at least a partial travel of the relative movement of the frame parts is brought by a separator bar, which holds the remainder of the pile, into contact with teeth arranged on a counter element, which teeth hold the individual sheet, and wherein means are provided for preventing direct contact between the separator bar and the teeth.
 33. Device according to claim 19, in which the retaining means for retaining the individual sheet comprises stop members (56) against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which means are provided for deforming the individual sheet in such a manner that its edge is positioned in front of the stop members for at least that partial travel of the frame parts during which this edge should act against the stop members.
 34. Device according to claim 19, in which the retaining means for holding the individual sheet comprises stop members against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which means (92) are provided which engage over the individual sheet edge and hold said edge in front of the stop members and, controlled by the relative movement of the frame parts, release said edge again.
 35. Device according to claim 19, in which the two separating elements are arranged on the same frame part and are displaceable relative to one another in the direction of the frame part movement and controlled by this movement.
 36. Device for the cyclic rearrangement of a pile of rectangular sheets, for example photographs, with a first (20) and a second (3) frame part which are movable backwards and forwards relative to one another and parallel to the principal plane of the pile, and with means which on movement of the frame parts backwards and forwards remove an individual sheet from one end of the pile and add said individual sheet to the other end of the pile again, which means comprise:(a) a separating means (36, 46) for separating the individual sheet from the pile, said separating means comprising a first and a second separating element which define a through-gap, (b) a feeding means (66) for feeding sheets to the separating means, (c) retaining means (50, 52, 56) for retaining the individual sheet in the first frame part and the remainder of the pile in the other frame part, and (d) guide means for guiding the separated individual sheet for the purpose of the remainder of the pile,in which means for deforming the individual sheet are provided in such a manner that the sheet has curves which space the remainder of the pile from the through-gap.
 37. Device according to claim 36, in which the means for deforming the individual sheet are constructed in such a manner that the sheet has curves running in the direction of movement of the frame parts.
 38. Device according to claim 36, in which the means for deforming the individual sheet are effective after entry of the individual sheet into a through-gap formed by the separating means.
 39. Device according to claim 38, in which the remainder of the pile, when not engaged by the feeding means, is spaced from the through-gap.
 40. Device according to claim 36, in which the deformation means comprise recesses and projections on the frame parts which engage one another in a comb-like manner.
 41. Device according to claim 40 wherein said projections and recesses of one of the frame parts are provided on the separating element arranged in said one frame part.
 42. Device according to claim 41, in which the projections of the other frame part are constructed as ribs which extend in the direction of movement of the frame parts.
 43. Device according to claim 42, in which the ribs are located in the region outside a through-gap for the individual sheet defined by the separating means.
 44. Device according to claim 36, in which the individual sheet is stiffened by the curves in the direction in which the frame parts move.
 45. Device according to claim 36, in which the separating means comprises a first and a second separating element which define a through-gap which, for the entry of the sheet to be separated, has an inside width of more than the thickness of one sheet and less than the thickness of two sheets, and in which the two separating elements are biassed resiliently towards one another only during an initial phase of the movement of the frame parts.
 46. Device according to claim 36, in which the separating elements for blocking the through-gap during that part of the frame part movement for which the feeding means is active are manually displaceable relative to one another.
 47. Device according to claim 36, in which the individual sheet during at least a partial travel of the relative movement of the frame parts is brought by a separator bar, which holds the remainder of the pile, into contact with teeth arranged on a counter-element which teeth hold the individual sheet, and wherein means are provided for preventing direct contact between the separator bar and the teeth.
 48. Device according to claim 36, in which the retaining means for retaining the individual sheet comprises stop members (56) against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which means are provided for deforming the individual sheet in such a manner that its edge is positioned in front of the stop members for a least that partial travel of the frame movement during which this edge should act against the stop members.
 49. Device according to claim 36, in which the retaining means for holding the individual sheet comprises stop members against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which means (92) are provided which engage over the individual sheet edge and hold said edge in front of the stop members and, controlled by the relative movement of the frame parts, release said edge again.
 50. Device according to claim 36, in which the two separating elements are arranged on the same frame part and are displaceable relative to one another in the direction of the frame part movement and controlled by this movement.
 51. Device for the cyclic rearrangement of a pile of rectangular sheets, for example photographs, with a first (20) and a second (30) frame part which are movable backwards and forwards relative to one another and parallel to the principal plane of the pile, and with means which on movement of the frame parts backwards and forwards remove an individual sheet from one end of the pile and add said individual sheet to the other end of the pile again, which means comprise:(a) a separating means (36, 46) for separating the individual sheet from the pile, (b) a feeding means (66) for feeding sheets to the separating means, (c) retaining means (50, 52, 56) for retaining the individual sheet in the first frame part and the remainder of the pile in the other frame part, and (d) guide means for guiding the separated individual sheet for the purpose of returning said individual sheet to the other end of the remainder of the pile,wherein the separating means comprises a first (46) and a second (36) separating element which define a through-gap, and in which the separating elements for blocking the through-gap during that part of the movement of the frame parts for which the feeding means is active are manually displaceable relative to one another by means of a manual operator movably connected to one of said frame parts.
 52. Device according to claim 51, in which the displaceable separating element can be returned to its initial position by the other separating element.
 53. Device according to claim 51 with a separating element displaceable by sliding.
 54. Device according to claim 51, in which the displaceable separating element can be locked to the frame part in which said displaceable separating element is arranged.
 55. Device according to claim 54, in which the displaceable separating element is constructed to lock itself when displaced back to its original position.
 56. Device according to claim 51, in which the displaceable separating element is resiliently deformable at least in some parts.
 57. Device according to claim 56, in which the displaceable separating element is resiliently biassed towards the other separating element.
 58. Device according to claim 51, in which the through-gap has a height which is greater than the thickness of one sheet and less than that of two sheets, and wherein the two separating element are biassed towards one another only during an initial phase of the movement of the frame parts.
 59. Device according to claim 51, in which one of the separating elements (36) forms the holder for the remainder of the pile, while the other separating element is arranged on a separate insert (40) in the first frame part and during the initial phase of the movement of the frame parts is resiliently biassed towards the one separating element.
 60. Device according to claim 51, in which means are provided for deforming the individual sheet in such a manner that said individual sheet has curves which space the remainder of the pile from the through-gap.
 61. Device according to claim 51, in which the separating elements for blocking the through-gap during that part of the frame part movement for which the feeding means is active are manually displaceable relative to one another.
 62. Device according to claim 51, in which the individual sheet during at least a partial travel of the relative movement of the frame parts is brought by a separator bar, which holds the remainder of the pile, into contact with teeth arranged on a counter-element, which teeth hold the individual sheet, and wherein means are provided for preventing direct contact between the separator bar and the teeth.
 63. Device according to claim 51, in which the retaining means for retaining the individual sheet comprises stop members (56) against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which means are provided for deforming the individual sheet in such a manner that its edge is positioned in front of the stop members for a least that part of the frame movement during which this edge should act against the stop members.
 64. Device according to claim 51, in which the retaining means for holding the individual sheet comprises stop members against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which means (92) are provided which engage over the individual sheet edge and hold said edge in front of the stop members and, controlled by the relative movement of the frame parts, release said edge again.
 65. Device according to claim 51, in which the two separating elements are arranged on the same frame part and are displaceable relative to one another in the direction of movement of the frame parts and controlled by this movement.
 66. Device for the cyclic rearrangement of a pile of rectangular sheets, for example photographs, with a first (20) and a second (30) frame part which are movable backwards and forwards relative to one another and parallel to the principal plane of the pile, and with means which on movement of the frame parts backwards and forwards remove an individual sheet from one end of the pile and add said individual sheet to the other end of the pile again, which means comprises:(a) a separating means (36, 46) for separating the individual sheet from the pile, (b) a feeding means (66) for feeding sheets to the separating means, (c) retaining means (50, 52, 56) for retaining the individual sheet in the first frame part and the remainder of the pile in the other frame part, and (d) guide means for guiding the separated individual sheet for the purpose of returning said individual sheet to the other end of the remainder of the pile,in which the individual sheet during at least a partial travel of the relative movement of the frame parts is brought by a separator bar, which holds the remainder of the pile, into contact with teeth arranged on a counter-element, which teeth hold the individual sheet, and wherein means are provided for preventing direct contact between the separator bar and the teeth.
 67. Device according to claim 66, in which the teeth can be disengaged from the individual sheet as the frame parts are pushed together.
 68. Device according to claim 67, in which the teeth oppose the movement of the frame parts away from each other.
 69. Device according to claim 67, in which the teeth can be spaced relative to the individual sheet.
 70. Device according to claim 69, in which the spacing can be carried out manually.
 71. Device according to claim 70, in which the counter-element is accessible from outside the device.
 72. Device according to claim 67, in which a distance spacing said teeth from said individual sheet is controlled by the movement of the frame parts.
 73. Device according to claim 66, in which, in the region of the teeth, the separator bar has recesses and laterally of these has projections which hold the individual sheet against the teeth.
 74. Device according to claim 73, in which, the separator bar recesses have a rounded contour.
 75. Device according to claim 66, in which the teeth lie under spring bias against the individual sheet.
 76. Device according to claim 75 with a pressing system for pressing the pile against a viewing window arranged in one of the frame parts, wherein the teeth are arranged on the pressing system for the pile.
 77. Device according to claim 75, in which the teeth are pushed out of a leaf spring.
 78. Device according to claim 66, in which the counter-element is arranged on the floor of one of the frame parts.
 79. Device according to claim 66, in which the teeth are constructed on at least one edge of the counter-element.
 80. Device according to claim 66, in which the teeth are arranged symmetrically with respect to a plane of symmetry running at right angles to the principal plane of the pile and in the direction of movement of the frame parts.
 81. Device according to claim 80 with two rows of teeth which extend parallel to the direction of movement of the frame parts.
 82. Device according to claim 80, in which the counter-element has a U-shaped basic outline with the teeth on the free arms.
 83. Device according to claim 82, in which the base of the U is manually operable from the outside for displacing the counter-element into a position in which the teeth are disengaged from the individual sheet.
 84. Device according to claim 66, in which the separating means comprises a first (46) and a second (36) separating element which define a through-gap which, for the entry of the sheet to be separated, has an inside width of more than the thickness of one sheet and less than the thickness of two sheets, and wherein the two separating elements are biassed resiliently towards one another only during an initial phase of the movement of the frame parts.
 85. Device according to claim 66, in which one of said separating means (36) forms the holder for the remainder of the pile, while the other separating means is arranged on a separate insert (40) in the first frame part and during the initial phase of the movement of the frame parts is resiliently biassed towards the one separating means.
 86. Device according to claim 66, in which means are provided for deforming the individual sheet in such a manner that said individual sheet has curves which space the remainder of the pile from the through-gap.
 87. Device according to claim 66, in which the separating means for blocking a through-gap during that part of the frame part movement for which the feeding means is active are manually displaceable relative to one another.
 88. Device according to claim 66, in which the retaining means for retaining the individual sheet comprises stop members (56) against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which means are provided for deforming the individual sheet in such a manner that its edge is positioned in front of the stop members for a least that partial travel of the frame movement during which this edge should act against the stop members.
 89. Device according to claim 66, in which the retaining means for holding the individual sheet comprises stop members against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which means (92) are provided which engage over the individual sheet edge and hold said edge in front of the stop members and, controlled by the relative movement of the frame parts, release said edge again.
 90. Device according to claim 66, in which the two separating elements are arranged on the same frame part and are displaceable relative to one another in the direction of movement of the frame parts and controlled by this movement.
 91. Device for the cyclic rearrangement of a pile of rectangular sheets, for example photographs, with a first (20) and a second (30) frame part which are movable backwards and forwards relative to one another and parallel to the principal plane of the pile, and with means which on movement of the frame parts backwards and forwards remove an individual sheet from one end of the pile and add said individual sheet to the other end of the pile again, which means comprise:(a) a separating means (36, 46) for separating the individual sheet from the pile, (b) a feeding means (66) for feeding sheets to the separating means, (c) retaining means (50, 52, 56) for retaining the individual sheet in the first frame part and the remainder of the pile in the other frame parts, and (d) guide means for guiding the separated individual sheet for the purpose of returning said individual sheet to the other end of the remainder of the pile,and in which the retaining means for retaining the individual sheet comprises stop members (56) against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which means are provided for deforming the individual sheet in such a manner that its edge is positioned in front of the stop members for a least that partial travel of the frame movement during which this edge should act against the stop members.
 92. Device according to claim 91, in which the deformation means are constructed for a corrugated deformation of the individual sheet.
 93. Device according to claim 92, in which the deformation means comprise projections and recesses on both frame parts which engage each other in a comb-like manner.
 94. Device according to claim 93, in which the projections and recesses of one of the frame parts are provided on the separating element thereof.
 95. Device according to claim 94, in which the projections of the other frame part are constructed as ribs which extend in the direction of the relative movement of the frame parts.
 96. Device according to claim 95, in which the ribs extend for the greatest part of the travel of the relative movement.
 97. Device according to claim 91, in which the stop members are arranged fixedly in the first frame part.
 98. Device according to claim 91, in which a pressing arrangement is provided which presses the pile towards a viewing window arranged in one of the frame parts, and wherein the stop members form a part of the pressing arrangement.
 99. Device according to claim 91, in which the stop members form a part of the feeding means.
 100. Device according to claim 91, in which the separating means comprises a first (46) and a second (36) separating element which define a through-gap which, for the entry of the sheet to be separated, has an inside width of more than the thickness of one sheet and less than the thickness of two sheets, and wherein the two separating elements are biassed resiliently towards one another only during an initial phase of the movement of the frame parts.
 101. Device according to claim 91, in which one of the separating means (36) forms the holder for the remainder of the pile, while the other separating means is arranged on a separate insert (40) in the first frame part and during the initial phase of the movement of separating means.
 102. Device according to claim 91, in which means are provided for deforming the individual sheet in such a manner that said individual sheet has curves which space the remainder of the pile from a through-gap.
 103. Device according to claim 91, in which the separating means for blocking a through-gap during that part of the frame part movement for which the feeding means is active are manually displaceable relative to one another.
 104. Device according to claim 91, in which the individual sheet, during at least a partial travel of the relative movement of the frame parts, is brought by a separator bar, which holds the remainder of the pile, into contact with teeth arranged on a counter-element which teeth hold the individual sheet, and wherein means are provided for preventing direct contact between the separator bar and the teeth.
 105. Device according to claim 91, in which the two separating elements are arranged on the same frame part and are displaceable relative to one another in the direction of movement of the frame parts and controlled by this movement.
 106. Device for the cyclic rearrangement of a pile of rectangular sheets, for example photographs, with a first (20) and a second (30) frame part which are movable backwards and forwards relative to one another and parallel to the principal plane of the pile, and with means which on movement of the frame parts backwards and forwards remove an individual sheet from one end of the pile and add said individual sheet to the other end of the pile again, which means comprise:(a) a separating means (36, 46) for separating the individual sheet from the pile, (b) a feeding means (66) for feeding sheets to the separating means, (c) retaining means (50, 52, 56) for retaining the individual sheet in the first frame part and the remainder of the pile in the other frame part, and (d) guide means for guiding the separated individual sheet for the purpose of returning said individual sheet to the other end of the remainder of the pile,and in which the retaining means for retaining the individual sheet comprises stop members against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which there are provided means (92) which engage over the individual sheet and hold said individual sheet in front of the stop members and, controlled by the relative movement of the frame parts, release said individual sheet again.
 107. Device according to claim 106, in which a pressing arrangement is provided which presses the pile towards a viewing window arranged in one of the frame parts, and wherein the stop members form a part of the pressing arrangement.
 108. Device according to claim 106, in which the means engaging the sheet and the individual sheet are displaceable relative to one another in the direction of movement of the frame parts between a retaining position and a releasing position.
 109. Device according to claim 108, in which the engaging means are displaceable relative to the stop members and the individual sheet.
 110. Device according to claim 106, in which the stop members form a part of the feeding means.
 111. Device according to claim 110, in which the means engaging the sheet are displaceable relative to the pressing arrangement in the direction of movement of the frame parts between a retaining position and a releasing position.
 112. Device according to claim 110, in which the means engaging the sheet are displaceable in the direction of movement of the frame parts between a retaining position and a releasing position relative to the feeding means.
 113. Device according to claim 106, in which the engaging means are constructed as hooks (92).
 114. Device according to claim 106, in which the stop members and the engaging means are arranged symmetrically with respect to an axis of symmetry running at right angles to the principal plane of the pile and parallel to the direction of movement of the frame parts.
 115. Device according to claim 106, in which the engaging means are displaceable approximately at the reversal point of the movement of the frame parts into a release position.
 116. Device according to claim 106, in which the stop members and the engaging means with the edge of the individual sheet held by them are constrained during the rearrangement to move substantially at right angles to the principal plane of the pile.
 117. Device according to claim 106, in which the separating means comprises a first (46) and a second (36) separating element which define a through-gap which, for the entry of the sheet to be separated, has an inside width of more than the thickness of one sheet and less than the thickness of two sheets, and wherein the two separating elements are biassed resiliently towards one another only during an initial phase of the movement of the frame parts.
 118. Device according to claim 106, in which a first separating means (36) forms the holder for the remainder of the pile, while a second separating means is arranged on a separate insert (40) in the first frame part and during the initial phase of the movement of the frame parts is resiliently biassed towards the first separating means.
 119. Device according to claim 106, in which means are provided for deforming the individual sheet in such a manner that said individual sheet has curves which space the remainder of the pile from the through-gap.
 120. Device according to claim 106, in which the separating means for blocking a through-gap during that part of the frame part movement for which the feeding means is active are manually displaceable relative to one another.
 121. Device according to claim 106, in which the individual sheet during at least a partial travel of the relative movement of the frame parts is brought by a separator bar, which holds the remainder of the pile, into contact with teeth arranged on a counter-element which teeth hold the individual sheet, and wherein means are provided for preventing direct contact between the separator bar and the teeth.
 122. Device according to claim 106, in which the two separating elements are arranged on the same frame part and are displaceable relative to one another in the direction of movement of the frame parts and controlled by this movement.
 123. Device according to claim 106, in which the engaging means can be inserted between the individual sheet and the remainder of the pile as soon as the individual sheet has been displaced with respect to the remainder of the pile for a predetermined distance by means of the movement of the frame parts.
 124. Device according to claim 123, in which the engaging means are mechanically de-actuable by the remainder of the pile.
 125. Device according to claim 123, in which the engaging means press the sheet of the remainder of the pile facing the individual sheet away from the individual sheet during the insertion.
 126. Device for the cyclic rearrangement of a pile of rectangular sheets, for example photographs, with a first (20) and a second (30) frame part which are movable backwards and forwards relative to one another and parallel to the principal plane of the pile, and with means which on movement of the frame parts backwards and forwards remove an individual sheet from one end of the pile and add said individual sheet to the other end of the pile again, which means comprise:(a) a separating means (36, 46) for separating the individual sheet from the pile, (b) a feeding means (66) for feeding sheets to the separating means, (c) retaining means (50, 52, 56) for retaining the individual sheet in the first frame part and the remainder of the pile in the other frame part, and (d) guide, means for guiding the separated individual sheet for the purpose of returning said individual sheet to the other end of the remainder of the pile,wherein the separating means comprises a first and a second separating element which define a through-gap which, for the entry of the sheet to be separated, has a height of more than the thickness of one sheet and less than the thickness of two sheets, and in which the two separating elements are arranged on the same frame part and are displaceable relative to one another in the direction of movement of the frame parts and controlled by this movement.
 127. Device according to claim 126, in which one of the separating elements comprises:a support for supporting at least the edge of the individual sheet facing the through-gap, a step defining the gap height, and a contact face on the top side of the step farthest away from the individual sheet edge, and in which the other separating element is displaceable along the top face towards the step and over this.
 128. Device according to claim 127, in which the one separating element is arranged fixedly in the frame part.
 129. Device according to claim 127, in which the other separating element has wedge-like faces on its side facing the top face.
 130. Device according to claim 127, in which the support and the top face are defined by substantially level flat portions parallel to one another.
 131. Device according to claim 126, in which the separating elements are arranged on the first frame part.
 132. Device according to claim 126, in which the displaceable separating element is pivotable with a moving component in the direction of movement of the frame parts.
 133. Device according to claim 132, in which two substantially mirror-symmetrically arranged, displaceable separating elements are provided.
 134. Device according to claim 133, in which the displaceable separating elements are pivotable about bearings arranged laterally with respect to the pile.
 135. Device according to claim 134, in which the displaceable separating elements are pivotable about axes which extend substantially at right angles to the principal plane of the pile.
 136. Device according to claim 135, in which the displaceable separating elements are arranged on the first frame part and the second frame part has control members which pivot the separating elements as they run on.
 137. Device according to claim 136, in which the displaceable separating elements are displaceable between a resting position, in which they extend substantially parallel to the through-gap, and a pivoted-out position, in which they extend substantially parallel to the direction of movement of the frame parts.
 138. Device according to claim 137, in which the displaceable separating elements are constrained to move by the control members between the two positions.
 139. Device according to claim 136, in which the displaceable separating elements can be pivoted by the control members from the resting position into the extended position, and can be returned by spring force into their resting position.
 140. Device according to claim 140, in which the displaceable separating elements are pivotable between a resting position, in which they extend substantially parallel to the through-gap, and a holding position, in which they hold the individual sheet against a support.
 141. Device according to claim 140, in which the displaceable separating elements are pivotable by the control members at the start of the movement of the frame parts from the resting position into the holding position and can be returned to the resting position close to the reversal point of the movement of the frame parts.
 142. Device according to claim 141, in which a releasing device actuated by the second frame part is provided for returning the displaceable separating elements.
 143. Device according to claim 126, in which the two separating elements are resiliently biassed towards one another only during an initial phase of the movement of the frame parts.
 144. Device according to claim 126, in which one of the separating elements is arranged on a separate insert in the first frame part.
 145. Device according to claim 126, in which means are provided for deforming the individual sheet in such a manner that the sheet has curves which space the remainder of the pile from the through-gap.
 146. Device according to claim 126, in which the separating elements for blocking the through-gap during that part of the frame part movement for which the feeding means is active are manually displaceable relative to one another.
 147. Device according to claim 126, in which the individual sheet during at least a partial travel of the relative movement of the frame parts is brought by a separator bar, which holds the remainder of the pile, into contact with teeth arranged on a counter-element which teeth hold the individual sheet, and wherein means are provided for preventing direct contact between the separator bar and the teeth.
 148. Device according to claim 126, in which the retaining means for retaining the individual sheet comprises stop members (56) against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which there are provided means for deforming the individual sheet in such a manner that its edge is positioned in front of the stop members for at least that partial travel of the movement of the frame parts for which this edge should be acting against the stop members.
 149. Device according to claim 126, in which the retaining means for retaining the individual sheet comprises stop members against which an edge of the individual sheet running transversely to the direction of the relative movement of the frame parts acts as the frame parts are moved apart, and in which there are provided means which engage the individual sheet and hold it in front of the stop members and, controlled by the relative movement of the frame parts, release it again. 